Ignis Fatuus
by Ericka Jane
Summary: UPDATED: MAY 2018. His magic is positively screaming, unable to withstand the thought of Arthur being hurt, of failing to keep him safe. He knows the consequences, but he won't be able to live with himself if Arthur gets tortured because of him. Not if he can stop it. Hurt!Merlin, Gen, H/C.
1. 1

Timeline: Season/series 4, post 'Aithusa.'

Tags/Warnings: Hurt!Merlin, Torture, Protective!Arthur, Magic!Reveal, general creepiness, and fluff.

Update 2018: Thank you for all of the great support and feedback! I was nervous venturing from my ride-or-die fandom but everyone has been so amazing. I more-or-less re-wrote this whole story because I felt like there was so much more to tell, and while I was editing my plot bunny came back for revenge. Whether you're reading this for the first or second time, I appreciate it and I hope you enjoy!

 **Ignis Fatuus**

 _n: Latin, "Foolish fire;" A deceptive goal or hope._

* * *

Merlin wakes to a burning in his shoulders that could rival fire. Blinking away the heaviness from his eyes, he finds out why: his wrists are locked in heavy shackles anchored to the cave ceiling, pulling his arms tight enough to lift his heels from the ground. Merlin can feel the magic pulsing in the cave and flowing through his restraints. Cautiously, he reaches out with his own magic, gently probing the darker energy. The magic surrounding the metal is strong but Merlin can tell that his is stronger.

"Merlin, wake up."

Arthur's voice pulls his attention away from the bonds. Across the cave, Arthur's wrists are in identical shackles, with his arms spread out and secured to the cave walls. Despite their predicament, Merlin's relieved that Arthur isn't strung up like he is, tearing his arms from the joints and struggling to breathe.

"I am awake," Merlin croaks.

Arthur's eyes narrow, hearing the pain in his servant's voice, but any response the king may have is interrupted by the appearance of their captor. The towering, dark figure glides into Merlin's vision, drawing close enough that he expects to feel the monster's breath on his face. He pulls back as far as the manacles will let him.

Merlin doesn't know what to call it. They were captured before he could return to Gaius to find out more about the creature that has been stalking him for weeks. The shape and movements of the entity could pass as a man, but the corpse-like features of its face make it undeniably evil. Most of its features are indistinguishable, except for its wide human-like mouth, sharp jaw, and glowing eyes. The skin that he can see is insect-like: tight, thin, and near translucent in color. The wraith stands a full head taller than Merlin, even with his body stretched impossibly far in his chains. It stares down at him with narrowed, cloudy eyes.

 _"Confess."_

Merlin knows what it wants and it's the one thing he will never give, no matter the consequences.

The sorcerer swallows and whispers, "Never," praying that Arthur doesn't hear it.

The wraith's mouth twitches, looking pleased as if it had been hoping for that answer. Slowly, it reaches into it's tattered robes and pulls out a long, curved dagger from the folds.

Merlin tracks the movement and lands his eyes on the blade. It really isn't the dagger that scares him, nor is it the dead, white eyes of the creature that's holding it - it's knowing that he's going to die with Arthur knowing what he is, and he won't get the chance to explain.

 _"Confess."_

Within the tight confines of his bonds, Merlin shakes his head 'No.'

The wraith is slow at first, caressing his skin with the blade as if introducing him to it. The knife is sharp and precise enough that the sting of pain doesn't come until the edge leaves his skin. The initial contact makes him gasp but he quickly presses his lips together, telling himself that he won't give it the satisfaction, or cause Arthur more pain than necessary by making a sound.

With the knife temporarily at the wraith's side, Merlin drops his head back and tries to force more air into his chest. The torturous feeling of his lungs struggling to expand under his ribcage may kill him before the creature can get its confession.

 _"Confess."_ Blood drips from the knife, landing on the stones at Merlin's feet with a sick sound.

"I have nothing to confess," Merlin says as he stares into the black void under the creature's hood.

Without a sound, the wraith raises the dagger once more. The sharp edge pushes against Merlin's clavicle, deeper this time, gliding in a diagonal line underneath his collarbone. Merlin bites his lip hard and refuses to so much as groan.

 _"Confess."_

Across the cave, Arthur growls, "Whatever it is you want from him, he doesn't have it. He's a only a servant."

Merlin can hear Arthur struggling against his bonds, cursing through clenched teeth when it gets him nowhere. Merlin closes his eyes and tries to focus on the pain, on staying in the present. If he focuses on Arthur it might make him do something stupid, like cry or plead for Arthur to get them out of this.

The next strike takes him by surprise. The knife makes a long, vertical cut down his torso, crisscrossing the previous laceration and ending before his navel. It's deep, and he can't stop the short, pain-filled shout from escaping his throat.

"Merlin!" Arthur yells.

 _"Confess."_

Blood begins to trickle down his torso, soaking into the waistband of his trousers, making his skin itch.

"I will confess to nothing," Merlin spits out.

The wraith seems amused by his defiance as it pauses to consider him. It steps impossibly closer and hisses, _"You will,"_ with so much conviction and pleasure that it makes Merlin shiver.

Merlin tries to ignore how unnerved he feels by the proximity of the wraith as he tightens his jaw and says, "I will never tell you anything."

"Merlin, shut up," Arthur demands from behind them, "Stop trying to be a hero."

The wraith reaches out a bony hand and wraps it around Merlin's throat, but it doesn't squeeze. Instead, it puts just enough pressure on his windpipe to remind him of how easy it would be to crush him.

 _"Confess."_

Merlin grits his teeth in disgust, feeling the leathery texture of its fingers against his skin, "No."

Enraged by Merlin's refusal, the wraith circles around him and brings the knife up the length of Merlin's back in one swift, furious stroke, cutting deeper than any of the previous wounds. The scream that comes out is unintentional but Merlin still tries to bite it down, hyper-aware of the fact that Arthur is watching him.

"Bastard," Arthur growls, "Let him go! He knows nothing!"

Merlin spits the saliva that's built up in his mouth, "Arthur, please…"

Arthur doesn't even know what the wraith wants from him, hasn't even tried to guess. As far as Arthur knows, this is just another thing that's happened to them, another life-or-death situation that they'll somehow find their way out of. Arthur has no idea that this is all Merlin's doing, and the guilt is almost as painful as his bleeding wounds.

The wraith first showed itself in Merlin's dreams, haunting him, showing him visions of Uther dying and Morgana laughing. Days later it was in the market, stalking him from behind carts, passing around people unknowingly, like a spirit. At first, Merlin thought he had been seeing things - just fleeting shadows out of the corner of his eye. But soon it became bolder, showing it's full form and venturing closer, and Merlin couldn't deny it any longer. Before he could work a solution out with Gaius, Arthur demanded that they go on a solo hunting trip to, "Relax." They were ambushed in the woods when they stopped to make camp. The thing was so fast, Arthur barely had time to draw his sword before they were both incapacitated.

 _"Confess."_

Merlin takes a few breaths and looks Arthur in the eye for the first time since this started. For the moment Arthur is safe and Merlin is going to make sure he stays that way. Arthur must see the resolve on his face because he shakes his head in frustration, and begins pulling on his restraints with renewed vigor.

"I have nothing to confess to," Merlin finally says.

The wraith is vibrating with rage and Merlin prepares himself for the next attack, but it doesn't come. Instead, the creature takes the dagger, still slick with blood, and approaches one of the torches illuminating the cave. Then, it slowly brings the knife up to the torch and holds it over the open fire.

Merlin's throat bobs. He knows what's coming.

"No!" Arthur shouts, the panic in his voice bounces off the stone, "Take me! Take me, he can't help you!"

"Arthur, it's going to be alright," Merlin says, his voice hitching. His lungs feel like they're caving in, and it's only made worse by his rapidly increasing fear. He can't take his eyes off the knife, steadily glowing brighter as it becomes hotter.

The wraith moves from the torch and pulls out the glowing blade. Despite the reassurance he gave to Arthur, Merlin is terrified of what's coming. The creature leers at him, drawing closer and closer. Merlin's feet scramble on the cave floor, trying to find purchase to flee, but the shackles don't budge.

The monster stops in front of him, brand in hand, offering Merlin one last chance to save himself. Merlin can see the glint of sharp, animal-like teeth as it grins at him from behind the knife.

 _"Confess."_

He wants to, god does he want to, but he won't. There's one thing that will hurt him more than fire, more than steel, and it's the look of hatred that he knows he'll see in Arthur's eyes if he ever finds out what he really is. His destiny is with Arthur, and no amount of pain is going to take it from him, not as long as he can withstand it.

So Merlin swallows, looks it in the eye, and says, "No."

The wraith steps behind him, by design, Merlin is sure, so Arthur can see his face when the hot blade touches his skin. It grabs his shoulder with one hand, holding him in place with a punishing grip.

"Merlin, look at me," Arthur demands.

Merlin opens his eyes, not even realizing that they were closed. He can feel the heat crawling closer to his skin, and he has to force himself to keep breathing.

"Look at me. It's going to be alright," Arthur says, his face a complete mask of bravery, trying to stay strong so Merlin will as well.

Nothing can stop the inhuman scream that tears from him when the scalding hot metal presses into the small of his back. He can hear Arthur yelling but he doesn't know what he's saying, if he's even saying anything at all. There's nothing but agony and fire, and it seems to last forever until finally, the blade is removed. Merlin's body quakes; he wants nothing more than to collapse on the cold cave floor and never wake up. He knows it's bad because what was once excruciating pain is now dulling into numbness.

 _"Confess."_

"No." A string of saliva escapes his mouth as his head hangs down over his chest. Merlin struggles to push down the vomit that's threatening to come up.

The wraith pulls away and smoothly walks back to the torch, re-heating the blade that's still impossibly hot. It stares at him as if it's happy to be doing it.

"Please," Merlin begs, swallowing down the sobs that want to escape, "Please don't do this, please."

The wraith doesn't react, just continues to let the blade heat up to an absolutely punishing temperature.

He can't hold back the tears any longer but his struggling lungs refuse to let him weep in earnest. If he wasn't so scared he'd be absolutely humiliated over the fact that he's losing it in front of Arthur, but right now all he can think about is the pain that he knows is coming.

"Merlin, listen to me," Arthur pleads, "Just tell it. Whatever it is, just give it what it wants." Arthur sounds positively wrecked like he's hurting just as much as Merlin is.

If only it could be that easy. It's all he's ever wanted, to tell Arthur and to be accepted. To be able to tell Arthur everything he's done, the good and the bad, to explain that his entire existence relies upon staying by his side. But after what happened with Uther's death only a month ago, Merlin knows that it can never happen. Arthur hates magic now more than ever.

So he's going to let the monster hurt him, no matter what the cost, no matter how long it lasts.

"I can't, Arthur," Merlin sobs, "I'm sorry."

The wraith moves away from the fire, pulsing hot blade in hand. Merlin whimpers as it draws near, too weak to try and push away. The creature reaches out with a skeletal hand and clenches Merlin's jaw with bruising strength.

 _"Confess."_

Merlin's terrified, he can feel his magic bubbling up, aching to lash out and prevent the assault. He stomps it down, pushing it to a place that's less threatening. It calms for the moment but Merlin has no idea if he's going to be able to keep it in place through the next round of torture.

It's hard, it's so much harder than anything he's ever done before, but he says, "No."

With a sneer, the creature turns from him and stalks over to where Arthur's being restrained. Unadulterated panic fills Merlin's body, making every nerve ending sing with adrenaline.

"No!" Merlin shouts, "Don't! It's supposed to be me!"

The creature grabs the opening of Arthur's tunic and rips it open. Arthur's chest is heaving but he's silent, jaw tight and eyes forward. The creature grabs a handful of Arthur's hair and yanks his head back and hisses, _"Confess."_

"Let him go," Merlin commands, "It's me you want. Don't touch him."

It smiles widely, knowing that it's finally found the one thing that is able to weaken the sorcerer. Merlin's stomach turns over as the glowing orange blade moves closer to the exposed skin on Arthur's torso.

His magic is positively screaming, unable to withstand the thought of Arthur being hurt, of failing to keep Arthur safe. He knows the consequences but he won't be able to live with himself if Arthur gets tortured because of him. Not if he can stop it.

He lets his magic go. It explodes from him like a storm: loud, bright, and powerful. The black cave is encased in blinding white light that swallows the creature whole. Arthur turns his face into his shoulder, blocking out the worst of it. It lasts until Merlin is spent, exhausted from pain and trauma. The light fades slowly and when it's gone, the creature is too. The last thing Merlin sees before he passes out is the shock on Arthur's face.


	2. 2

**2**

* * *

The rocks from the cave wall dig into his back, carving out bruises that he knows will be there for days. He's annoyed. Something got the drop on them in the woods and not only defeated him with no trouble at all but also managed to capture him and his servant.

Merlin.

Arthur doesn't know why yet, but the creature seems more interested in his manservant than it is the crowned King of Camelot. Merlin, on the other hand, doesn't seem surprised at all, which is more than a little troubling.

He tests his bonds by pulling and twisting. They're solid and judging by the heat they're putting off, they have also been spelled.

Sorcery. Fantastic.

Arthur's begrudged to admit that they're not going to get out of this, at least not their usual way. They're going to have to wait for someone to miss them long enough to come looking.

The creature paces in front of Merlin. His servant watches it carefully but doesn't seem to be afraid. Instead, Merlin's wearing a familiar expression of defiance and irritation. A flash of pride flickers up inside of Arthur. For as useless as he is as a servant and as a fighter, Arthur knows Merlin doesn't lack bravery. As long as they both stay strong they'll be able to get through this.

 _"Confess,"_ The creature hisses at Merlin.

Arthur frowns. Confess? What the hell would his servant need to confess for?

Merlin doesn't say anything, which seems to annoy the creature. From its black robes, it produces a long, ornate dagger. Merlin sees it too and falters slightly, but then carefully steels his expression again, rebuilding the stubborn walls that Arthur has seen time and time again.

"I have nothing to confess," Merlin says.

The creature steps forward so that it's blocking Merlin from Arthur's view. Even though he can't see it happen, Arthur knows by the hiss of pain that comes from his servant that the creature has touched him with the blade.

When the creature moves Arthur can see the rather shallow cut that it left on Merlin's pectoral muscle. Dread makes its way down his spine. If the creature is willing to do this, it's willing to do more. And knowing stupid, stubborn Merlin, he isn't going to make it easy on himself.

 _"Confess."_

"I will confess to nothing."

Idiot.

"Whatever it is you want from him, he doesn't have it. He's a just a servant!"

Maybe he can get the creature to focus on him instead. He doesn't know what it wants from Merlin but he knows Merlin doesn't have it. It's _Merlin_ , for god's sake.

But the creature ignores him and Merlin does too. The knife catches the reflection of the torches as it glides through the air once more, ripping through Merlin's vulnerable skin. He can tell Merlin's trying to keep quiet, but he can still hear the muted grunt that he makes when the creature cuts him. When he's able to lay eyes on Merlin again, he's able to see the dark trails of blood rolling down his thin torso, dripping onto his boots. Merlin's eyes are screwed shut and his chest is heaving like it's taking all of his effort to focus on breathing. Rage starts building up in Arthur's chest. Merlin won't be able to last very long like this; the position of his body alone will eventually kill him.

Then the creature reaches out a disgusting hand and completely closes it around Merlin's throat. Arthur's heart thunders in his chest, and he begins pulling on his chains in a way that will cause injury to himself before they ever give. He doesn't care about the way his skin chafes under the metal cuffs, he can't just watch as that thing suffocates Merlin.

 _"Confess."_

He sees Merlin hesitate a moment longer than he has with the previous answers, but he still grits out, "No."

The creature is inhumanely fast, slicing open Merlin's torso before either of them know what's happening. For the first time Merlin screams, but it catches in his throat as he tries to force it down in a show of bravery.

"Bastard!" Arthur shouts, "Let him go! He knows nothing!" He pulls and pulls on the chains. Around Arthur's wrists, the shackles begin to grow hotter from the restraining magic.

"Arthur, please…"

At first, Arthur isn't sure if Merlin is pleading to him for help, or to keep quiet, but when Merlin lifts his head it becomes clear: Merlin plans to see this through to the end, whatever that end may be.

 _"Confess."_

Merlin meets Arthur's eyes when he says, "I have nothing to confess to," and Arthur has never hated his servant's stubbornness more.

Merlin continues to deny the creature a confession, and Arthur can see it growing angrier and angrier with every blow with the knife. Soon, it loses patience. The creature stalks over to a torch and begins to heat up the dagger over the flame. The dread that curls up in Arthur's stomach could make him vomit. He sees Merlin's eyes widen and he knows that his servant has worked out what's going to happen as well.

"No! Take me! Take me, he can't help you!" Arthur shouts, trying desperately to free himself or draw the creature's attention to him. Anything but letting it burn Merlin.

But the creature doesn't move, doesn't even acknowledge him.

"Arthur, it's going to be alright," Merlin's voice is shaking despite the reassuring words.

Only Merlin. Only Merlin would be trying to console him right now as if Arthur's the one about to be descended upon with a red-hot blade. Arthur's equal parts proud and infuriated by his servant's words. Most men would be sobbing right now, begging and pleading, confessing anything to stop the monster from burning them, but Merlin's first thought is to reassure his king. His friend.

Arthur has never felt so helpless and it makes his blood boil.

He watches as the creature moves behind Merlin with the glowing blade and gods, the thing is smiling. Wide, bright white teeth pull across the thing's face, taking up an unnatural amount of space, relishing in Merlin's pain and fear. Arthur tears his eyes away from it and focuses on Merlin instead.

"Merlin, look at me. Look at me. It's going to be alright," Arthur makes sure his face doesn't give anything away. He needs to be strong. If Merlin sees him break than he won't stand a chance of holding it together. Merlin's eyes meet his and the trust, the resignation there, makes Arthur want to tear the monster apart piece by piece.

When it happens, when that thing presses the white-hot blade into Merlin's back, Arthur feels like a piece of him breaks. The agonizing sound that Merlin makes will haunt his nightmares forever.

When it's over and Merlin is silent, so silent, Arthur realizes that he was screaming too. God, Merlin looks awful. Spit, blood, and sweat drips from his shaking body. The creature seems satisfied that its prey has lost its defiance. It leans over Merlin's shoulder and hisses in his ear, "Confess."

Merlin flinches away but chokes out, "No."

Arthur can tell that the creature is infuriated. It wrenches itself away from Merlin's body and immediately goes back to the torch to re-heat the knife.

Merlin breaks for the first time and starts to beg, and Arthur just can't take it anymore.

"Merlin, listen to me," Arthur pleads, "Just tell it. Whatever it is, just give it what it wants."

Whatever it is the creature thinks Merlin knows, it can't be bad enough to continue to withstand all of this.

Merlin looks like he wants nothing more to give in, but instead of voicing a confession, he mutters, "I can't, Arthur. I'm sorry."

The creature is done with the flame, and Arthur can see Merlin's labored breathing increase in fear. But the creature surprises them both when it approaches Arthur instead. The King's heart begins to race but he thinks finally. Finally, it's away from Merlin.

Merlin doesn't share the sentiment.

His servant starts shouting the stupidest things like, _"It's supposed to be me!"_ and _"It's me you want!"_

Arthur hasn't been able to protect him this entire time, but even if it's by the pain of fire, he's going to protect him now.

The creature tears open his shirt and Arthur doesn't flinch. He's going to face this like he faces everything else: with the bravery that would make his knights proud.

But it doesn't happen. The cave fills with an otherworldly light so bright that it could rival the sun. Arthur has to close his eyes to protect himself from the blinding luminosity. From beside him, he can hear the creature let out a distressed screech before everything begins to still. As the light fades Arthur is able to open his eyes and seek out Merlin.

He's not prepared for what he sees. Merlin's eyes are burning a bright, brilliant gold - the same color of gold that Arthur has seen blaze in the eyes of the sorcerers he's killed. The gold slowly fades into Merlin's usual brilliant blue before his eyes slide shut, and Merlin hangs limply in his chains. The shackles holding Merlin unlatch with a loud 'snick' and the servant crumbles to the ground. Arthur jerks forward on reflex and doesn't meet resistance. The king regains his balance and looks at the cave wall in surprise. The shackles didn't just unlock, they disappeared altogether, leaving behind nothing but wet cavern stone.

Arthur's unsettled by the missing restraints but he shakes it off, crawling over to his fallen servant. He turns Merlin onto his back, searching for signs of life. Merlin's chest hitches on every breath and his skin is cold and clammy, and not at all reassuring.

Arthur doesn't know what to do.

Merlin has magic. Merlin is a _sorcerer_. A sorcerer who just vanquished a mysterious creature without a word or any help at all, and now appears to be on death's door because of it.

Arthur stares at the numerous injuries on his servant's pale skin and decides to approach this as if he were caring for any other person who has been injured in battle: Seek shelter, tend to the wounds, and regroup.

He thinks about trying to wake Merlin but decides against it; better for him to rest while he can and be oblivious to the pain. Slowly, Arthur carefully gathers Merlin in his arms, whispering apologies when the injured man whimpers. He begins to set out of the cave with his servant over his shoulder, hoping beyond hope that the horses are still where they left them.

He treks over the slippery terrain carefully, trying not to shift Merlin too much and thanking every god he knows of that the man doesn't weigh more.

The horses come into view and Arthur breathes a sigh of relief. It felt like they were in the cave for days, but judging by the position of the sun they were only missing for a few hours. His back aches from the weight of his manservant and the time he spent chained to the cave wall. He's beyond grateful when he can finally drape Merlin over his horse to relieve the pressure.

The ride back to Camelot is at least a day away. In normal circumstances, they could easily make it, but Arthur is hesitant to push their luck with Merlin so badly injured. He's angry, but the last thing he wants to do is cause Merlin any unnecessary pain.

A few yards away Arthur spots his fallen sword. He makes sure Merlin is secure on the horse before retrieving it from the grass. The weight of the blade is immediately comforting but it doesn't bring the same feeling of peace that it usually does.

More than anything Arthur wishes that they never went on this hunting trip. He wants to be back in the castle with his annoying servant messing up the easiest of tasks, and talking back to him while he does it. He wants to go back before he knew what Merlin sounds like when he's being cut open, back before he knew the truth.

Arthur still doesn't even really understand what happened in the cave or what the creature was. It was obvious that its purpose was to reveal Merlin's magic, but to what end? To see Merlin executed? To just cause them both pain? Why Merlin?

Feeling frustrated at the lack of answers, Arthur decides to focus on the only thing he can control, which is getting them both back to Camelot alive.

* * *

Arthur's plan of riding through the night to reach Camelot fails when Merlin breaks into a fever and almost flings himself from the horse. Arthur curses and rushes to Merlin just in time to keep him from sliding to the ground.

Merlin is drenched in sweat, tossing his head in a fitful sleep. After a moment of indecision, Arthur lifts Merlin and positions him on his own horse, before hauling himself up behind him. Arthur silently apologizes to his mare for the extra weight but urges on.

Draped over the horse in front of him, Merlin squirms as the fever rages. From this angle, Arthur has a completely unobstructed view of the injuries his servant sustained from the torture. The cuts are bad but stopped bleeding some time ago, it's the burn that has Arthur worried. The wound is deep, Arthur can see the divot in the flesh from where it was burned out. The skin is a rainbow of angry reds and unnatural whites, and Arthur pushes away the nauseating thought of it being deep enough to reveal bone.

He wonders if the cause of Merlin's sickness is from his wounds or the expulsion of magic. Arthur has known about magic his whole life but most of what he was taught centered around how evil and manipulative it was. At no point was he taught about what happens to sorcerers when they extinguish shadow creatures without even lifting a hand, and until now, he's never cared.

With these thoughts in mind, Arthur shoves down his fear and pushes his horse a little harder. If Merlin's fever and sickness are being caused by his own magic, Arthur has no hope of saving him.

* * *

They make camp at the river and Arthur begins the task of cleaning Merlin's wounds. The lacerations are the easiest; he wipes away the blood and coats the lacerations with one of Gaius' healing salves.

The easy part done, Arthur assesses the burn on the small of Merlin's back. He's not looking forward to touching it, unconscious or not, he's sure it's going to cause his servant pain.

With a deep sigh, he braces Merlin with one hand on his shoulder and gently begins to lay the balm on the ruined skin. As anticipated, Merlin makes a wounded sound and immediately arches, trying to pull away from the touch.

Arthur shushes him and murmurs an apology. Merlin's eyes blink open slowly, and for a moment, Arthur swears he sees gold in them.

"Please...stop…" Merlin's face is half turned into his sleeping pack, but Arthur can hear the fevered words all the same, and despite his anger, they stab at his heart.

"It's alright, you're safe now," Arthur reassures, and gently squeezes the shoulder that's under his hand.

But Merlin doesn't hear him, as darkness claims him once more.

* * *

Neither of them can sleep. Every time Arthur closes his eyes he's back in the cave, listening to Merlin scream, and unable to do anything to help. Merlin mutters and cries out in his sleep, caught in fevered dreams that don't seem any more pleasant than Arthur's.

Arthur keeps watch instead, resting against the base of a tree close to Merlin, listening for the sounds of threats. The simplicity of the woods is soothing, a stark contrast to the turmoil he's feeling.

There have been times over the years where he believed his father to be wrong about many things, including magic. Uther had a blind hate for magic that clouded his judgement in the best of times, and turned him positively ruthless in the worst of times. There was never a time in Arthur's life where Uther showed anyone with magic mercy.

Some of Arthur's earliest memories are of public executions and warnings from his father on the dangers of sorcerers. But even as a child he remembered looking into the crying faces on the pyre and wondering how they could be dangerous when they looked so scared.

On his worst sleepless nights he thinks about whether or not he's ever done the right thing when it comes to magic. He thinks about people such as Gwen's father and the Druids that were slaughtered under his watch, and wonders what kind of king he'll be if he allowed those people to die. Some nights he feels vindicated, because he knows that magic is dangerous and has caused many people pain. But most of the time he's just angry, because he knows he was his father's sword and executioner, and at the time he felt like he didn't have any other choice.

And now there's Merlin, and the choice is no ones but his own.

There are so many things that make sense now that he knows the truth: the luck they always have while facing an enemy, the miraculous recoveries from near death, the awful luck they always seem to have when they go hunting…

Merlin. All of it was Merlin. It had to be.

Arthur's brought out of his thoughts when Merlin shifts in his sleep, grimacing and opening his eyes for the first time in hours. He can see the confusion in Merlin's gaze, made worse by the burning fever and lingering pain. He reminds Arthur of a child, vulnerable and searching for something to anchor to.

Arthur picks up the wet cloth that he's been using in an attempt to keep Merlin cool and places it on his forehead.

"Lie still," Arthur says, pushing the cool cloth into Merlin's skin, "It's just a fever."

Merlin doesn't appear to understand, but he seems to settle when Arthur puts his hand on his forehead.

"My back…"Merlin mutters.

Arthur swallows and hopes that his servant will just go back to sleep so he doesn't have to answer. What is he supposed to say? Your back is mangled? I'm sure it'll heal? I'm sorry I couldn't stop it?

"Try not to move," He says instead, keeping a firm hand on Merlin's shoulder.

"How bad?"

Arthur rolls his eyes. Even injured and delirious, the man is still insufferably stubborn.

"I cleaned the wounds the best that I could and covered the burn with ointment, but you need a real physician. I'll get you back to Gaius, he'll be able to help."

"Arthur…"

Arthur can tell by the tone of Merlin's voice that he's going to bring up the magic, and it's the last thing that Arthur wants to deal with at the moment.

"I don't want to talk about it," Arthur says in a tone that leaves no room for discussion, "Let's just get back to Camelot."

There's a dead silence that follows and he knows Merlin is still awake. He can feel Merlin's need to speak, to explain, and it sets Arthur's teeth on edge. He's just not ready to face more lies or explanations. Not yet.

After a moment Merlin finally closes his eyes, and Arthur tries not to notice that they're wet with tears.

Once he's sure Merlin is asleep again, Arthur sighs and leans his head back against the tree. All he wants is to get back to the castle, throw himself into training, and forget that today ever happened. Maybe then Arthur will feel like he can breathe again.

* * *

The next morning Merlin is deep in the throes of fever, and Arthur can barely wake him.

He tries pressing water to his servant's lips in hopes of getting him to drink and calm the heat, but it's useless. Merlin is trapped in his own mind, moaning out pleas and begging for an invisible creature to stop hurting him.

With panic clutching at his chest, the king gathers his servant and mounts his horse with Merlin in his arms. They ride hard and as fast as his horse can manage, all the while he whispers apologies as Merlin groans in discomfort.

Merlin can't die. He cannot lose his stupid, self-sacrificing servant, regardless of what he is or is not. It's just not an option.

When the castle comes into view Arthur almost sobs with relief. He sees Leon as soon as they're through the gates, conversing with other knights in the courtyard.

"Leon!" Arthur yells and hopes he doesn't sound as desperate as he feels.

His knight snaps his head up and immediately breaks into a run, "Sire! Are you hurt?"

"Help me get him down," Arthur demands, already shifting Merlin's weight to make him easier to maneuver. He lowers his servant down to Leon's waiting arms as gently as possible, trying hard to ignore his knight's horrified expression as he takes in Merlin's injuries.

He dismounts and gets the attention of one of the knights that are nearby, "Tell the court physician that the king requires his assistance immediately!"

Arthur watches the knight run the direction of the physician's quarters and feels the tightness in his chest ease slightly.

"We need to get him to Gaius," Arthur says and takes Merlin from Leon's arms.

Arthur is unreasonably grateful that Leon doesn't ask any questions, just hands Merlin over and follows him as they sprint to Gaius' quarters.

Gaius looks heartbroken but stone-faced when Arthur comes bursting into the room with Merlin in his arms.

"Put him here," Gaius says and points to a nearby cot, "Carefully. I need water, his fever is burning badly."

Leon answers the request with, "Right away," and quickly leaves to retrieve a bucket.

"What can I do?" Arthur asks as he watches the old physician gather various bottles and jars.

"I think you've helped enough, sire. Your field bandaging most likely saved his life," Gaius replies as he carefully peels back the strips of cloth from Merlin's skin.

He gets to the burn and his hands falter, "What weapon caused this?"

"A knife," Arthur answers darkly, "Cutting him wasn't doing the job, so it got creative."

Gaius doesn't respond. He doesn't ask what happened, who did it, or what it wanted, which confuses Arthur. If it were him he'd be asking all of these questions and then some, but Gaius is acting like he isn't surprised, like he already knows.

Does he? Arthur wonders. Aside from himself, Merlin is closest to Gaius; if anyone were to know Merlin's secret, it'd be the magic-reformed physician.

"Did you know?" Arthur's trying to stay calm, but he can't quite keep the accusation out of his voice.

Gaius is unfazed and barely looks up from Merlin, "Know what?"

"Did you know that Merlin is a sorcerer? Did you know about...about that thing?"

Gaius stills, but only for a moment, before he calmly answers, "Yes."

Gaius has all of the bandages off Merlin now, leaving a clear view of angry, red skin and seeping blood. Arthur watches as the physician puts his hand on Merlin's forehead as if checking the temperature, and then tenderly pushes his hair back like a father would do to a child. The old man's hands tremble as he repeats the motion.

Resolutely, Gaius meets his eyes, "I will answer as many questions as I can, and if you must, you can arrest me. I won't resist. But please, sire. Let me save him."

Arthur feels like he's been kicked in the chest. Gaius actually thinks Arthur would do that, just wrench away the only person in the kingdom who can save Merlin's life, all because of sorcery. For a brief moment, Arthur hates his father. He hates that the man instilled so much fear and so much resentment in all of them in his crusade against magic. He wonders what his father would do at this moment, standing before one of his oldest friends, who has been harboring a sorcerer for years. But Arthur knows, as definitively as he knows anything: Uther would jail Gaius, and sentence Merlin to death, leaving him to rot in the dungeon in his fevered state for his last night on earth. Merlin would be shown no mercy.

There's no doubt that Gaius knows this as well. Despite their differences in temperament, Arthur is still Uther's son, and right now, Gaius doesn't know what kind of king he's going to be.

It's all too much. Knowing that Merlin is in the safest place he can be, Arthur turns and leaves, not saying a word.

He has to get out.


	3. 3

**3**

* * *

They build the largest pyre in Camelot's history for the execution, the first of King Arthur's reign. The structure stands like a tower, dwarfing the silent onlookers and red-cloaked knights. Arthur doubled the guard for this execution, worried about attempted rescues and escapes. The drums echo through the court and the spectators part, allowing the guards to march the sorcerer to the pyre, silently. He's half dragged, half marched up the steps to the stake but he doesn't struggle against the guard's hands. The silence doesn't break until the guards begin to chain the sorcerer to the pyre.

"Arthur, please," Merlin pleads, his voice breaking. The guards wrench his arms behind his back, "I'm innocent. Please, Arthur, you have to believe me."

Arthur doesn't react as he watches the guard step off the platform. The drums tap steadily and Arthur brings down his arm, motioning for the guard to lower the torch.

It goes up faster than any pyre Arthur has witnessed before, swallowing the wood in seconds. As it burns Merlin thrashes, pulling against the chains, face twisted in agony. Something dark in the center of the pyre catches Arthur's eye, and he squints, trying to get a clearer view. The flames recede and standing behind the stake is an inhumanely tall figure, cloaked in flowing black robes, completely untouched by the fire. It stares at Arthur unwaveringly, motionless as Merlin begins to slacken in his bonds. Then it reaches out and drags it's skeletal hand down Merlin's face, smiling with wide teeth.

 _"Confess."_

Arthur wakes with a start, jumping out of bed in an instant with a sword in hand. The word echoes around his room so clearly that Arthur is sure the creature is with him.

Arthur searches through the darkness, expecting to catch a glimpse of white eyes. But the room is silent and empty, save himself.

Releasing the breath he didn't know he was holding, Arthur drops his sword on the bed and sits on the edge, head in his hands.

He hasn't been able to sleep since they returned to Camelot days ago. Every time he tries he's plagued with dreams of torture, pyres, and shadow figures.

And Merlin.

The dreams are always different. Sometimes Merlin burns silently, reduced to nothing but ash and bones. Other times he screams and pleads until his lungs fill with smoke. The worst ones are when they're back in the cave and the creature tortures his servant until he's limp in the chains, and no longer breathing.

And Arthur has no idea why.

They went through an ordeal, there's no doubt about it. But Arthur has faced undead armies and the Dorocha, and while those experiences were certainly unpleasant, none of them have affected him like this.

A voice in his head whispers, _"Sorcery,"_ but Arthur pushes it away, ignoring how much it sounds like his father's.

He hasn't been to check on Merlin since he brought him to Gaius almost three nights ago. Instead, he's relied on reports from his knights to make sure that he's still alive. They all stare at him strangely when they bring news, no doubt wondering why he hasn't been to visit himself. The only one to actually bring it up was Gwaine.

 _"Why don't you go find out how Merlin's doing from Merlin?" The knight asked after he gave his report._

 _Arthur just glared, readying a retort about him being the king and not having to answer to anyone._

 _"It's funny," Gwaine said, ignoring Arthur's harsh look, "Merlin doesn't seem to fancy you coming to see him either. What happened in that cave?"_

 _Gwaine and his knowing, accusing eyes made Arthur feel guilty, and it infuriated him to no end._

 _Merlin is the liar. Merlin is the sorcerer._

 _Instead of answering his knight, he dismissed Gwaine harshly and spent the rest of the day shredding a training dummy._

That was this morning. Now, sitting in his too-dark and too-quiet chambers, Arthur wonders if Gwaine was right, and he just needs to see Merlin for himself.

He can't admit it to his knights but it's fear that's kept him from visiting his servant. What if Merlin's condition is worse than what he's been told? What if when he sees him, Arthur can only see a sorcerer and not his closest friend?

Before he didn't want to know the answer to any of these questions, but something about this last nightmare has him on edge and he finds he can't let it be. Before he even knows what he's doing, he's out of his room and making his way to the physician's chambers.

* * *

Arthur stares at Gauis' door, wondering if he should knock and feeling foolish for being so hesitant. Exhaling, Arthur pushes the door open slowly, wincing as it protests loudly. The room is warm and quiet, glowing from the array of candles placed on every available surface. Gaius is nowhere to be seen but Merlin is asleep on the cot, tossing and turning. Arthur watches from the doorway, unsure of what to do and questioning whether or not he made the right choice in coming.

"Can I help you, sire?"

Arthur jumps, startled by the older man's sudden presence. Gaius stares at the king with thinly veiled distrust and Arthur immediately knows what Gaius must be thinking.

"I was just…"

Gaius lifts an eyebrow.

"I don't know," Arthur finally admits.

"I see," Gaius says and walks past the king, moving to soothe Merlin's thrashing body.

Arthur watches the physician pull up a stool to Merlin's bedside, grabbing hold of his charge's hands as they clench the sheets. Merlin doesn't look like a dangerous sorcerer. He just looks scared. Tortured.

"Easy, my boy. It will pass," Gaius soothes.

Arthur feels a flash of envy at the fatherly display but quickly stomps it out.

"Has he been having nightmares?" Arthur asks.

"Yes," Gaius begins to use a cool cloth to dampen Merlin's forehead, "He's still with fever. It makes the dreams worse."

Merlin gasps harshly and Arthur flinches, remembering the same sound from when the creature began to cut Merlin open.

"I've had a few dreams as well," Arthur admits.

Gaius looks at him with curiosity, "Nightmares? This started the night you returned?"

Arthur nods, "Do you think it means anything?"

The physician stands from the stool and moves to grab a tonic from the shelf, "Sometimes nightmares are just nightmares, sire. But whatever took you was of magic. This could be a symptom of the ordeal you went through."

More magic. The very last thing that Arthur wants to think about.

Gaius hands him a dark blue tincture.

"This is to help you sleep. It hasn't done Merlin much good, I'm afraid, but perhaps it will bring you peace."

"Thank you," Arthur says.

Gaius quirks a half smile and Arthur feels as if he's been forgiven for something.

From the cot Merlin thrashes, catching the attention of the physician. Wordlessly, Gaius returns to his ward, dipping the cloth back into the nearby bucket, and placing it on Merlin's forehead.

Arthur stands awkwardly in the doorway, clenching the tincture in his hand. Arthur feels as if he should leave and yet, something is anchoring him, refusing to let his feet move.

"Arthur, no!" Merlin kicks in his sleep, fighting off an invisible foe. Arthur feels stricken and wonders if Merlin dreams of executions as often as he does. The thought makes him sick.

Gaius hushes his charge and for a moment Merlin calms. Then he looks back at Arthur, heartbreak evident on his face.

"There's nothing he wouldn't do for you, Arthur. Surely you must know that."

"I do," Arthur says and finds himself surprised that he believes it.

* * *

Merlin's eyes are sticky with grit when he opens them. The room is softly lit and Gaius moves around silently, mixing poultices and boiling herbs. Merlin watches every movement, letting the mundane and familiar motions chase away the last of his nightmares. Sometimes his sleep is dreamless, but more often than not it's plagued with caves, white teeth, and screams that aren't his own. It's worse when he wakes in the dark; he thinks that's why Gaius has taken to keeping candles lit late into the night.

Gaius turns around and notices that he's awake.

"You have good timing. I was just going to wake you to change your bandages," Gaius says, making his way over to the cot, "How is your pain?"

"How long?" Merlin's voice crackles with disuse, and his throat flares when he swallows.

Gaius' expression turns dark, "Almost four days now, in and out of consciousness."

Merlin can tell from the sound of his mentor's voice that it hasn't been an easy four days.

"The way Arthur tells it, you're lucky to have gotten out alive," Gaius continues while he pulls up a stool to Merlin's cot.

At the mention of the king, it all comes rushing back: Merlin had used his magic to save them. He had used magic in front of Arthur.

"He knows," Merlin gasps while trying to sit up. He regrets it immediately and is gently pushed back down by Gaius' guiding hands.

"Gaius! Arthur…"

"Knows. I know," Gaius confirms, face remaining neutral, "He was here a few nights ago while you were still unconscious."

"What did he say?" Merlin asks, fingers digging into his pillow. He can't stand the not knowing, wondering if Arthur's planning on jailing him or worse, wondering if the most important person in his world now hates him.

"Not much, I'm afraid," Gaius says apologetically. He begins to peel the bandages off his ward's back, working quickly but gently.

Merlin stares and his heart pounds, "How can you be so _calm_ about this?"

"He hasn't ordered your arrest," Gaius says, "And that's all you need to worry about right now."

Silence passes between them as Merlin worries his bottom lip between his teeth. Gaius works diligently, coating each wound with healing balms and re-dressing them meticulously.

"I'm sorry that you had to experience this, my boy," Gaius says sadly, "The creature. It was...as we feared?"

Merlin nods and tries not to think of wide, white teeth and glowing eyes, "It doesn't matter anymore. Arthur still found out."

"And yet here you are," Gaius reassures, "That must count for something."

"He's probably just mulling over what punishment will be best suited." Merlin's desperately trying not to think of cold iron and pyres, or how Arthur would look if Merlin were to call for him from behind flames.

"I don't think you give him enough credit," Gaius stands up to dispose of the bloody bandages, "Give him time. He'll come around."

Merlin closes his eyes. Even if Arthur doesn't, Merlin won't let him run around Albion unprotected, not even if Arthur wants to see him burn.

* * *

It's been a week since the cave, most of which Merlin's spent sleeping and trying to keep the nightmares at bay. His back hurts something fierce but Gaius reassures him that the damage isn't permanent, but that there isn't much that can be done for the scarring. Scars are the least of Merlin's concerns right now.

"Do you think it's safe?" Merlin asks, sitting over a bowl of stew, "Arthur, I mean."

"I wish I knew," Gaius responds, as he watches his ward poke at his food. Merlin gulps down a spoonful of stew but looks absolutely green while he does it. He drops the spoon in defeat.

"He hasn't been back," Melin tries not to sound as despondent as he feels. The way Gaius raises an eyebrow tells him that he's been unsuccessful.

The knights all came to visit: Gwaine, Elyan, Leon, and Percival. Gwen came and offered him a sympathetic smile and a reassuring hug. Merlin watched them all wearily as they came through the door, searching for signs of distrust or hate, but found none. So Merlin knows that Arthur hasn't told anyone, but has no idea what that means.

* * *

The next morning Merlin is past the point of fear and has moved right on to anger. Arthur has given him the cold shoulder for over a week, allowing him to stew in his anxiety and pain, wondering if each and every moment was going to be _the_ moment.

He storms through the castle - or tries to, as much as his body will allow - ignoring the alarmed looks that people throw at him. Merlin only has one thing on his mind and it's finding out whether or not he needs to flee Camelot to save his skin.

Merlin shoves open Arthur's doors without preamble.

Arthur looks up from his writing desk and rolls his eyes, "Still not knocking, I see. You do remember that I'm the king, don't you?"

Merlin doesn't even pause, "What is your problem?"

"Sorry?" Arthur puts down the parchment he was reading, "My problem?"

"Do you even remember what happened? Dark, nasty cave? Monosyllabic wraith? Unbearable torture? Ringing any bells?" Merlin waves his arms and immediately winces, forgetting that his body is still an injured mess, "How can you just sit in here, while I'm down _there_ wondering if at any minute the guard is going to kick down my door, and drag me to the chopping block?!"

Distantly Merlin thinks that this probably isn't his best move, antagonizing the very person he's trying to plead clemency to. Merlin exhales slowly, calming his turbulent emotions.

"I have magic, Arthur. I always have," Merlin's breath hitches and he's horrified to find his throat tightening and eyes stinging, "And I wanted to tell you, so many times. I'm sorry that you found out this way."

Merlin sniffs and scrubs his face with his sleeve, bracing himself for Arthur's reaction.

"Are you finished?" Arthur asks

Merlin nods.

"Good. Sit down before you fall down, you great idiot."

That's when Merlin notices that he's barely standing, leaning heavily enough that it would only take a soft breeze to knock him over. Arthur is at his side before he knows what's happening, shoving him into a nearby chair. Sweat beads up on his skin and Merlin wonders when it got so hot in Arthur's room.

"I'm to assume that Gaius doesn't know you're here," Arthur says.

"Snuck out. Gaius was asleep at the table," Merlin admits, pushing his face into his hands. He tries to ignore the way his head is pounding and the way his stomach turns.

Arthur doesn't say anything. Merlin can feel the king's eyes burning into the top of his head but he can't bring himself to meet Arthur's gaze. He came here with the intention of facing Arthur head on and learning his fate, but now that it's staring him in the face, he can't find the strength to look.

"Come on," Arthur says softly, "Let's get you back to Gaius."

Merlin's head snaps up and Arthur rolls his eyes, "Don't look so surprised. I can't very well have you pass out in my chambers. I do still have a kingdom to run."

Merlin gapes but Arthur deliberately ignores him, throwing one of Merlin's arms over his shoulders, "C'mon, before Gaius kills us both."

They move slowly through the castle, stopping three times for Merlin to pant against the cool marble walls.

Gaius doesn't move when they come stumbling into the room, attesting to how worn down the older man truly is. Arthur helps Merlin back to the cot, slowly lowering the smaller man as he hisses in pain.

"Really, Arthur, you don't have to…"

"Merlin, shut up."

"But…"

"Shut. Up."

Arthur sits on the stool that Gaius has been permanently attached to ever since they came back. Merlin watches him through pain-filled eyes but underneath the discomfort, Arthur can see the very real fear staring back at him.

Arthur can't stop himself from asking the question that has been haunting him, "What was it? The thing in the cave?"

Merlin swallows, "A Tulpa. Sometimes thoughts and emotions are so strong that they can actually create beings, thoughtforms," Merlin pauses, wondering if he should continue. "After your father died and you denounced magic, I felt...hopeless. I've always believed that one day magi users would be free of fear but in that moment it seemed impossible. It took days to snap out of it but by then it was too late, the Tulpa was already appearing in my dreams."

"You created a monster whose sole purpose was to reveal your magic? All because you were upset?" Arthur asks incredulously.

Merlin winces, "Well, not on purpose. It wasn't going to stop until it was satisfied, until you knew the truth. It had been following me for weeks..."

" _Weeks?_ And you decided to carry on as normal and say nothing?" Arthur says, and rolls his eyes "Well done, Merlin. Brilliant plan."

"Well, I couldn't very well say, _'Arthur, a thoughtform is stalking me because hiding my magic is killing me,'_ could I?" Merlin bites back. He's angry. He's _scared_ , and Arthur still doesn't understand.

"No," Arthur's sudden softness in his voice and admission is the last thing Merlin is expecting, "I suppose not."

"No?" Merlin asks cautiously.

"I feel as if I've spent every moment as reigning king trying not to make the same mistakes as my father," Arthur says, his eyes giving away weeks of exhaustion, "His people feared him. I don't want my kingdom to live in the same fear."

"I thought you'd be angry," Merlin whispers in awe.

"I was. _I am_. You lied to me all this time and I just..." Arthur shakes his head, unable to keep the residual anger and hurt from his voice, "I spent the whole journey home thinking you were going to die, and then the next few days contemplating how much of a beating I was going to give you."

Merlin cracks a smile, "What changed?"

Arthur meets his eyes resolutely, "I realized that anyone who was willing to do what you did couldn't be anything but good, magic or not. I'm sorry that you ever felt like you were better off being tortured than telling me the truth. It never should've been that way."

Merlin swallows, unable to speak. He squeezes his eyes shut, allowing the built up tears to escape,"Thank you. You have no idea…"

He stops to breathe, trying to regain his composure.

"Just one thing," Arthur says after a moment.

Merlin opens his eyes warily, "What?"

Arthur leans forward, his expression hard, "If you ever conjure a torturing, kidnapping wraith again, I'll kill you."

Merlin snorts but then frowns, "That's not funny."

But Arthur laughs, truly, and Merlin can't help but smile in return. They're going to be alright.


End file.
